International audience In semi-arid to arid environments, water is the most constraining resource for agricultural communities. In Southeast Arabia (Sultanate of Oman and United Arab Emirates), the demographic growth and the increase of sites at the beginning of the Iron Age II (1100–600 b.c.) is generally attributed to the development of groundwater harvesting techniques, and more precisely to qanāt technology. While only little is known on the origin of this technology, even less is known about other hydraulic techniques, which could have been used as a complementary source of water. An irrigation system, recently discovered near an Iron Age settlement in the oasis of Masāfī (UAE) was studied thanks to the combination of various methods—archaeology, geoarchaeology/micromorphology, spatial analysis, and chronology—which have allowed us to identify the technological development of small-scale runoff farming and to link this practice to social as well as environmental issues